While debugging my site in Bali, I noticed it was doing requests to the domain cfs.u-ad.info, so I googled the domain and found several pages saying that Speedy (an ISP in Bali) injects a script which by the looks of it serves to insert ads into the websites. In my case however, the call being done by the script to cfs.u-ad.info returned an error, so no ad was injected.

I recommend someone takes a closer look to cfs.u-ad.info to consider adding it to the general blacklist. I don't speak Bahasa and I'm not in Indonesia anymore, so I leave this case to you guys. Good luck!